为探过镰刀菌属的系统发育情况,采用真核生物线粒体中核糖体小亚基基因(mtSSU rDNA)的通用引物,PCR扩增了2株不同生理小种(小种4和小种1)的香蕉枯萎病菌mtSSU rDNA序列,并对PCR产物进行了序列分析,同时利用MEGA4软件中的Neighbor-joining (N-J)法,对2个样品序列以及GenBank中登陆的镰刀菌属不同种及尖镰孢种不同专化型的mtSSU rDNA序列,构建聚类分析树状图.结果显示,所测的2株香蕉枯萎病菌mtSSU rDNA全长685 bp,两者之间同源性为99.70％.聚类分析表明,所测的2个样品和Fusarium oxysporum f.sp.cubense专化型在一个聚类组中,镰刀菌不同种及同种不同专化型间的mtSSU rDNA序列变异较大,说明该菌不同种及同种不同专化型间的遗传多样性丰富.%To explore the phylogenetic correlations among the strains of Fusarium spp. , the mitochondrial small subunit (mtSSU) rDNA genes from Fusarium oxysporum f. sp. Cubense in two physiological races (race4 and racel) were amplified by polymerase chain reaction using the mtSSU rDNA gene universal primers. Furthermore, phylogenetic tree was constructed on the basis of the two race mtSSU rDNA sequences and other mtSSU rDNA sequences of Fusarium spp. From GenBank by neighbor-joining method. The results showed that lengths of the gene in two races were 685bp and sequence homology between the two races was 99. 70%. Phylogenetic analysis suggested that the two sequences were clustered in the same group with the sequence of F. oxysporum f. sp. Cubense in the database. Meanwhile, there were variations in the mtSSU rDNA sequences of inter-species and the same species with different specialized obviously, suggesting that the abundant genetic diversity of mtSSU rDNA gene sequences could be used in phylogenetic and evolutionary analyses of Fusarium spp.
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